CVE-2021-22699

highpriority · track · 30EPSS 0.010 · 62 %ileEUUS

grimoire priorityP2 · Scheduled

Exploitable?

—

no known exploitation

Likely / severe?

0.98% (62nd) EPSS

CVSS 7.8 · high

Is it mine?

3 products

Check your exposure

Who says so?

3 sources

cnnvd · enisa_euvd · nvd

EPSS · scored 2026-10-28

Improper Input Validation vulnerability exists in Modicon M241/M251 logic controllers firmware prior to V5.1.9.1 that could cause denial of service when specific crafted requests are sent to the controller over HTTP.

cvss

Technical severity, 0–10. One row per scoring source.

7.8

010

base score 0–10 · higher = more severe · hover a vector to decode⚠ sources disagree · medium–high · 6.9–7.8

v2.07.8highAV:N/AC:L/Au:N/C:N/I:N/A:Cprimary · NVD / NIST USexploitability 10 · impact 6.9

v3.17.5highCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:Hprimary · NVD / NIST USexploitability 3.9 · impact 3.6

v3.16.9mediumCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H/E:Usecondary · CVSS-BT (t0sche)

weaknesses

The CWE weakness classes this flaw belongs to.

CWE-20US

affected products (3)

Products and version ranges known to be affected.

n/a Modicon M241/M251 logic controllers firmware prior to V5.1.9.1≤ Modicon M241/M251 logic controllers firmware prior to V5.1.9.1enisa_euvdEU
schneider-electric modicon m241 firmware< 5.1.9.1nvdUScpe:2.3:o:schneider-electric:modicon_m241_firmware:*:*:*:*:*:*:*:*
schneider-electric modicon m251 firmware< 5.1.9.1nvdUScpe:2.3:o:schneider-electric:modicon_m251_firmware:*:*:*:*:*:*:*:*

also known as (3)

Other names and identifiers for this entity.

sources

Which sources assert this record, and when.

cnnvd enisa_euvd nvd NVD CVE.org MITRE

published 2021-05-26modified 2026-06-17

references (3)

External citations — patches, advisories, analysis.

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